Computed tomography coronary angiography in patients with acute myocardial infarction without significant coronary stenosis.

BACKGROUND: It is known that a significant number of patients experiencing an acute myocardial infarction have normal coronary arteries or nonsignificant coronary disease at coronary angiography (CA). Computed tomography coronary angiography (CTCA) can identify the presence of plaques, even in the absence of significant coronary stenosis. This study evaluated the role of 64-slice CTCA in detecting and characterizing coronary atherosclerosis in these patients. METHODS AND RESULTS: Consecutive patients with documented acute myocardial infarction but without significant coronary stenosis at CA underwent late gadolinium-enhanced magnetic resonance and CTCA. Only the 50 patients with an area of myocardial infarction identified by late gadolinium-enhanced magnetic resonance were included in the study. All of the coronary segments were assessed for the presence of plaques. CTCA identified 101 plaques against the 41 identified by CA: 61 (60.4%) located in infarct-related arteries (IRAs) and 40 (39.6%) in non-IRAs. In the IRAs, 22 plaques were noncalcified, 17 mixed, and 22 calcified; in the non-IRAs, 5 plaques were noncalcified, 8 mixed, and 27 calcified (P=0.005). Mean plaque area was greater in the IRAs than in the non-IRAs (6.1±5.4 mm(2) versus 4.2±2.1 mm(2); P=0.03); there was no significant difference in mean percentage stenosis (33.5%±14.6 versus 31.7%±12.2; P=0.59), but the mean remodeling index was significantly different (1.25±0.41 versus 1.08±0.21; P=0.01). CONCLUSIONS: CTCA detects coronary plaques in nonstenotic coronary arteries that are underestimated by CA, and identifies a different distribution of plaque types in IRAs and non-IRAs. It may therefore be valuable for diagnosing coronary atherosclerosis in acute myocardial infarction patients without significant coronary stenosis.

Clinical characteristics and cardiovascular magnetic resonance findings in stress (takotsubo) cardiomyopathy.

CONTEXT: Stress cardiomyopathy (SC) is a transient form of acute heart failure triggered by stressful events and associated with a distinctive left ventricular (LV) contraction pattern. Various aspects of its clinical profile have been described in small single-center populations, but larger, multicenter data sets have been lacking so far. Furthermore, it remains difficult to quickly establish diagnosis on admission. OBJECTIVES: To comprehensively define the clinical spectrum and evolution of SC in a large population, including tissue characterization data from cardiovascular magnetic resonance (CMR) imaging; and to establish a set of CMR criteria suitable for diagnostic decision making in patients acutely presenting with suspected SC. DESIGN, SETTING, AND PATIENTS: Prospective study conducted at 7 tertiary care centers in Europe and North America between January 2005 and October 2010 among 256 patients with SC assessed at the time of presentation as well as 1 to 6 months after the acute event. MAIN OUTCOME MEASURES: Complete recovery of LV dysfunction. RESULTS: Eighty-one percent of patients (n = 207) were postmenopausal women, 8% (n = 20) were younger women (aged ≤50 years), and 11% (n = 29) were men. A stressful trigger could be identified in 182 patients (71%). Cardiovascular magnetic resonance imaging data (available for 239 patients [93%]) revealed 4 distinct patterns of regional ventricular ballooning: apical (n = 197 [82%]), biventricular (n = 81 [34%]), midventricular (n = 40 [17%]), and basal (n = 2 [1%]). Left ventricular ejection fraction was reduced (48% [SD, 11%]; 95% confidence interval [CI], 47%-50%) in all patients. Stress cardiomyopathy was accurately identified by CMR using specific criteria: a typical pattern of LV dysfunction, myocardial edema, absence of significant necrosis/fibrosis, and markers for myocardial inflammation. Follow-up CMR imaging showed complete normalization of LV ejection fraction (66% [SD, 7%]; 95% CI, 64%-68%) and inflammatory markers in the absence of significant fibrosis in all patients. CONCLUSIONS: The clinical profile of SC is considerably broader than reported previously. Cardiovascular magnetic resonance imaging at the time of initial clinical presentation may provide relevant functional and tissue information that might aid in the establishment of the diagnosis of SC.

CT coronary angiography for the follow-up of coronary stent.

The treatment of coronary artery stenosis has progressively shifted over the past decades, from surgical (CABG) to percutaneous (PCI and stenting). The recent introduction of drug-eluting stents further reduced the occurrence of in-stent re-stenosis (ISR). However, a non-negligible number of patients need imaging/functional tests when symptoms recur. Multi-Slice CT Coronary Angiography (CT-CA) is a clinical reality for the evaluation of coronary artery stenosis, but still under evaluation in the follow-up of coronary stents. Several factors may impair proper depiction of in-stent lumen even with the most recent CT equipments. In highly selected populations CT-CA may play a clinical role even though the performance requirements both from the technical standpoint (i.e., CT scanner) and from the training (i.e., operators' experience) are still very demanding. In the meantime CT technology should improve towards higher contrast, spatial and temporal resolution in order to achieve the results that may be proper for clinical implementation.

Predictive value of computed tomography coronary angiography for the evaluation of acute chest pain: single center preliminary experience.

AIM: To assess the predictive value of CT coronary angiography (CT-CA) in the stratification of patients with acute chest pain. MATERIALS AND METHODS: We enrolled 48 patients (31 males and 17 females, mean age 61.0 +/- 14yrs) with acute chest pain of suspected coronary origin, without diagnostic alterations of the ECG and/or increase of the myocardial biomarkers. Sixty-four slice CT-CA was performed within 48-72 hours. Depending on the clinical judgment, the patients were dismissed or underwent conventional coronary angiography (CAG). Patients underwent clinical follow-up at 6 months, recording the prevalence of major cardiovascular events. RESULTS: One patient was excluded from the analysis because of poor image quality. CT-CA showed no coronary artery disease in 38.3% (18/47) of the patients, no significant coronary artery disease (<50% lumen reduction) in 31.9% (15/47) of the patients, significant coronary artery disease (> or = 50% lumen reduction) in 29.8% (14/47) of the patients. In 87.2% (41/47) of the patients no indication for CAG was present. In 6 (12,8%) patients with significant stenosis at CT-CA indication for CAG was present. In 50% (3/6) of these patients, CAG showed no significant coronary artery disease and in the remaining 50%(3/6) CAG was followed by percutaneous coronary angioplasty. At follow-up no major cardiovascular events were observed. CONCLUSIONS: CT-CA showed high sensitivity for the detection of significant coronary artery disease and a negative predictive value at 6-month follow-up.

Diagnostic accuracy of computed tomography coronary angiography in a high risk symptomatic population.

OBJECTIVE: To evaluate the diagnostic accuracy of 64-slice computed tomography (CT) coronary angiography (CA) for the detection of significant coronary artery stenosis (> or = 50% lumen reduction) as compared to invasive coronary angiography (ICA) in a population of patients with chest pain and high risk. MATERIALS AND METHODS: 44 patients (30 male; mean age 60.2+/- 12.1 yrs) with chest pain were prospectively enrolled. In patients with heart rate > or = 70 bpm an oral dose of 100 mg of beta-blocker was administered. For CT-CA (Sensation 64, Siemens, Germany) an intravenous bolus of 100 ml of iodinated contrast material (Iomeron 400, Bracco, Italy) was injected. The average scan time was 13.3 +/- 0.9s. Two observers evaluated CT-CA vs. ICA as a reference standard for the detection of significant (> or = 50% lumen reduction) coronary artery stenosis. RESULTS: ICA demonstrated the absence of coronary artery disease (CAD) in 13.6% of the patients (6/44), the presence of non significant CAD 4.6% (2/44), single vessel disease in 27.2% (12/44) and multi-vessel disease in 54.6% (24/44) of the patients. None of the patients was excluded from the study population. Ninety-three significant obstructive coronary lesions were observed. Sensitivity, specificity, positive and negative predictive value of CT-CA were 98.6% (70/71), 92.4% (97/105), 89.7% (70/78) and 99% (97/98), respectively. All patients with at least one significant coronary lesion were correctly identified by CT-CA. CONCLUSIONS: CT-CA is a reliable alternative to ICA in a selected population of patients with chest pain and high risk.

Prognostic value of computed tomography coronary angiography in patients with suspected coronary artery disease: a 24-month follow-up study.

The aim of this study was to determine the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major cardiac events in patients with suspected coronary artery disease (CAD). A total of 187 consecutive patients (119 men, age 62.5 +/- 10.5 years) without known heart disease underwent single-source 64-slice CTCA (Somatom Sensation 64, Siemens) for clinical suspicion of CAD. Patients underwent follow-up for the occurrence of cardiac death, nonfatal myocardial infarction, unstable angina and cardiac revascularization. In total, 2,822 coronary segments were assessed. Forty-two segments (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed absence of CAD in 65 (34.7%) patients, nonobstructive CAD (coronary plaque < or =50%) in 87 (46.5%) patients and obstructive CAD (>50%) in 35 (18.8%) patients. A total of 20 major cardiac events (3 myocardial infarctions, 16 cardiac revascularizations, 1 unstable angina) occurred during a mean follow-up of 24 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD and three events occurred in the group of nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. CTCA has a 100% negative predictive value for major cardiac events at 24-month follow-up in patients with normal coronary arteries.

"In-house" pharmacological management for computed tomography coronary angiography: heart rate reduction, timing and safety of different drugs used during patient preparation.

We retrospectively evaluated the effect, timing and safety of different pharmacological strategies during 64-slice CT coronary angiography (CT-CA). From the institutional database of CT-CAwe enrolled 560 consecutive patients with suspected coronary artery disease. The type of drug preparation (group 1 = no treatment; group 2 = oral metoprolol; group 3 = other; group 4 = intravenous (IV) atenolol; group 5 = IV atenolol + nitrates; NR = non-responders), timing, and adverse effects were recorded. Heart rate (HR) during different preparation phases was recorded. Four adverse effects were recorded, none of which was attributable to pharmacological treatment. In all groups, except group 1, the HR on arrival was significantly reduced by the pharmacological treatment (p<0.01). Group 4 showed the best (-16±8 bpm) HR reduction. There was no significant effect on HR due to nitrates (p = 0.49), while a slight increase due to contrast material was noted (p<0.05). Average time required for preparation was 44±25min. Groups 4 and 5 showed the most effective timing (8±9 min and 8±8 min, respectively; p<0.01). Pharmacological preparation in patients undergoing CT-CA is safe and effective. Best results in terms of HR reduction and fast preparation are obtained with IV administration of beta-blockers.

CT angiography of the coronary arteries: setting new diagnostic standards in cardiovascular medicine.

Abstract. CT Coronary Angiography of the heart is one of the fastly developing techniques in cardiovascular imaging. It is rapidly emerging and quickly entering the clinical practice and international guidelines. The increasing evidence regarding the strong role in the assessment of coronary artery lumen is progressively expanded by evidences of the important role of coronary wall imaging. The prognostic importance of CT Coronary Angiography is worldwide reported and the main question that is posed at the moment concerns the potential impact in primary prevention. In this review we will discuss the current applications and technology state of the art, X-ray dose issues, the training requirements and implementation in the healthcare context of CT Coronary Angiography.

Tips and tricks in Multislice CT coronary angiography.

The introduction of the multislice computed tomography (MSCT) scanners and their application to coronary imaging has created a new clinical imaging field. Even though MSCT coronary angiography has been reported to be able to detect significant stenoses with very high diagnostic accuracy, the clinical implementation is still difficult and the users are having difficulties in reproducing the results in literature, partly due to the limited experience in the field of coronary MSCT. Several details can be overlooked so that diagnostic mistakes are possible. In this paper we tried to collect a series of technical "tips and tricks" that might improve the quality of coronary imaging in the clinical practice.

Non invasive imaging of coronary arteries with 64-slice CT and 1.5T MRI: challenging invasive techniques.

Non-invasive coronary artery imaging challenges any diagnostic modality, because of the complex and tortuous anatomy and cardiac contraction and respiration. Therefore, non-invasive coronary imaging requires high spatial and temporal resolution. Our purpose is to discuss the feasible applications in coronary imaging of Magnetic Resonance Imaging and Multi-slice Computed Tomography (MSCT). Focus will be devoted to potential indications and clinical impact of MSCT because of the fast development and the important results recently reported, in particular with the recent introduction of 64-slice equipments. MSCT of the coronary arteries is a promising imaging modality for the assessment of coronary lumen and wall.

Cardiac magnetic resonance imaging: Which information is useful for the arrhythmologist?

Cardiac magnetic resonance (CMR) is a non-invasive, non-ionizing, diagnostic technique that uses magnetic fields, radio waves and field gradients to generate images with high spatial and temporal resolution. After administration of contrast media (e.g., gadolinium chelate), it is also possible to acquire late images, which make possible the identification and quantification of myocardial areas with scar/fibrosis (late gadolinium enhancement, LGE). CMR is currently a useful instrument in clinical cardiovascular practice for the assessment of several pathological conditions, including ischemic and non-ischemic cardiomyopathies and congenital heart disease. In recent years, its field of application has also extended to arrhythmology, both in diagnostic and prognostic evaluation of arrhythmic risk and in therapeutic decision-making. In this review, we discuss the possible useful applications of CMR for the arrhythmologist. It is possible to identify three main fields of application of CMR in this context: (1) arrhythmic and sudden cardiac death risk stratification in different heart diseases; (2) decision-making in cardiac resynchronization therapy device implantation, presence and extent of myocardial fibrosis for left ventricular lead placement and cardiac venous anatomy; and (3) substrate identification for guiding ablation of complex arrhythmias (atrial fibrillation and ventricular tachycardias).

Evidence for a "gender paradox" in diabetic patients undergoing percutaneous coronary intervention: adverse preprocedural risk but favorable long-term clinical outcome in women.

BACKGROUND: The aim of this study was to assess the impact of gender on procedural and late clinical outcome in a large cohort of consecutive diabetic patients undergoing percutaneous coronary intervention (PCI) in a single center. METHODS: The study included a cohort of 542 consecutive diabetic patients (414 men, 128 women), undergoing PCI for stable and unstable angina. Clinical events were assessed every 6 months for a mean follow-up period of 24 months. RESULTS: Compared to men, women were older and less often smokers. Insulin requirement was present in a substantially higher percentage of women than men (27 vs 18%, p = 0.03). Presentation with stable angina was more frequent in women, whereas silent ischemia was more prevalent in men. Adverse baseline clinical and angiographic characteristics in women (smaller vessels and longer lesion lengths) were associated with a more frequent need for multiple coronary stenting (23 vs 15% women vs men, p < 0.001) and a higher incidence of peripheral complications (3.2 vs 1.2%, p = 0.049). However, there were no statistically significant gender-related differences in major in-hospital events. Long-term clinical outcome was similar with equivalent incidence of death (4.9 vs 5.3%, p = 0.8), nonfatal myocardial infarction (2.4 vs 4.5%, p = 0.1), need for surgical or repeat percutaneous revascularization between women and men. CONCLUSIONS: Diabetic patients show an increased rate of major adverse cardiac events and target vessel revascularization after PCI. In these patients, female gender is associated with higher procedural complexity and peripheral complications; however, long-term clinical outcome of diabetic women is similar to that of men.

[Non-invasive coronary angiography by multislice computed tomography: a new diagnostic method?]. / Coronarografia non invasiva mediante tomografia computerizzata multistrato: verso una nuova realtà diagnostica?

A significant improvement in the noninvasive evaluation of coronary anatomy has been obtained after the introduction of the new high-speed multislice computed tomography systems. Images are reconstructed using retrospective ECG-gated protocol along with contrast analysis and three-dimensional display algorithms. The 8 detectors and the reduced tube rotation time of last-generation scanners allow the coverage of the entire heart during a single breath-hold following an intravenous bolus of 120 ml of nonionic contrast. Faster computer software offers submillimeter resolution reconstructions and increased post-processing capabilities, such as quantitative angiography, virtual angioscopy, and calcium score evaluation. At least in this phase of technical development the visualization of side branches of coronary vessels seems to advantage multislice computed tomography with respect to nuclear magnetic resonance and electron-beam computed tomography in the challenge for clinical noninvasive evaluation of coronary microcirculation.

Detection of papillary muscle infarction by late gadolinium enhancement: incremental value of short-inversion time vs. standard imaging.

AIMS: Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can detect myocardial scar in patients with myocardial infarction. The detection of papillary muscle infarction (PMI) may be difficult due to the bright blood signal. The aim of our study was to evaluate the incremental value of LGE CMR imaging using an inversion recovery (IR)-GRE with a short-inversion time (TI) over standard LGE imaging in identifying PMI. METHODS AND RESULTS: Fifty-six patients with myocardial infarction were studied using a standard IR-GRE LGE sequence with an adjusted TI to null the signal intensity of normal myocardium and with a 3D IR-GRE with a short TI (<180 ms). Signal-to-noise and contrast-to-noise ratios (CNR) and the frequency of PMI were determined. Image quality and infarction sharpness were evaluated. The short-TI LGE sequence detected a higher number of PMI compared with standard LGE sequence (19/54 vs. 15/54) with an increased sharpness of PMI (84.2 vs. 53.3%). The CNR was higher between infarcted myocardium and blood (77.9 ± 60 vs. 19.3 ± 16, P < 0.001) and between PMI and blood (69.4 ± 51 vs. 39.4 ± 26, respectively, P = 0.0157). CONCLUSIONS: Our data indicate that in patients with myocardial infarction, LGE CMR imaging using a short TI may be more sensitive than standard LGE imaging for the detection of PMI.

Major adverse cardiac events and the severity of coronary atherosclerosis assessed by computed tomography coronary angiography in an outpatient population with suspected or known coronary artery disease.

PURPOSE: To investigate the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major adverse cardiac events (MACEs) in patients with suspected or known coronary artery disease (CAD). MATERIALS AND METHODS: Seven hundred and sixty-seven consecutive patients (496 men, age 62±11 y) with suspected or known heart disease referred to an outpatient clinic underwent 64-slice CTCA. The patients were followed for the occurrence of MACE (ie, cardiac death, nonfatal myocardial infarction, unstable angina). RESULTS: Eleven thousand five hundred and sixty-four coronary segments were assessed. Of these, 178 (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed the absence of CAD in 219 (28.5%) patients, nonobstructive CAD (coronary plaque ≤50%) in 282 (36.8%) patients, and obstructive CAD in 266 (34.7%) patients. A total of 21 major cardiac events (4 cardiac deaths, 12 myocardial infarctions, and 5 unstable angina) occurred during a mean follow-up of 20 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD, and 4 events occurred in the group with nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. In multivariate analysis, the presence of obstructive CAD and diabetes were the only independent predictors of MACE. CONCLUSIONS: Coronary plaque evaluation by CTCA provides an independent prognostic value for the prediction of MACE. Patients with normal CTCA findings have an excellent prognosis at follow-up.

Prediction model to estimate presence of coronary artery disease: retrospective pooled analysis of existing cohorts.

OBJECTIVES: To develop prediction models that better estimate the pretest probability of coronary artery disease in low prevalence populations. DESIGN: Retrospective pooled analysis of individual patient data. SETTING: 18 hospitals in Europe and the United States. PARTICIPANTS: Patients with stable chest pain without evidence for previous coronary artery disease, if they were referred for computed tomography (CT) based coronary angiography or catheter based coronary angiography (indicated as low and high prevalence settings, respectively). MAIN OUTCOME MEASURES: Obstructive coronary artery disease (≥ 50% diameter stenosis in at least one vessel found on catheter based coronary angiography). Multiple imputation accounted for missing predictors and outcomes, exploiting strong correlation between the two angiography procedures. Predictive models included a basic model (age, sex, symptoms, and setting), clinical model (basic model factors and diabetes, hypertension, dyslipidaemia, and smoking), and extended model (clinical model factors and use of the CT based coronary calcium score). We assessed discrimination (c statistic), calibration, and continuous net reclassification improvement by cross validation for the four largest low prevalence datasets separately and the smaller remaining low prevalence datasets combined. RESULTS: We included 5677 patients (3283 men, 2394 women), of whom 1634 had obstructive coronary artery disease found on catheter based coronary angiography. All potential predictors were significantly associated with the presence of disease in univariable and multivariable analyses. The clinical model improved the prediction, compared with the basic model (cross validated c statistic improvement from 0.77 to 0.79, net reclassification improvement 35%); the coronary calcium score in the extended model was a major predictor (0.79 to 0.88, 102%). Calibration for low prevalence datasets was satisfactory. CONCLUSIONS: Updated prediction models including age, sex, symptoms, and cardiovascular risk factors allow for accurate estimation of the pretest probability of coronary artery disease in low prevalence populations. Addition of coronary calcium scores to the prediction models improves the estimates.

The clue of ST-elevation myocardial infarction by means of integrated non-invasive imaging.

We describe the case of a 24-year-old man who presented at our emergency department with ST-elevation myocardial infarction (STEMI). The patient showed no coronary artery disease on conventional coronary angiography (CAG). Computed tomography coronary angiography (CTCA) and cardiac magnetic resonance (MR) performed thereafter allowed the highly probable diagnosis of the culprit lesion (i.e. vulnerable plaque) and of the infarcted area. We demonstrated the impact of integrated non-invasive imaging in defining the diagnosis of STEMI with normal coronary arteries on CAG.